Complementing the optical performance is an equally adept Hyper Sonic Motor, which provides fast, smooth, and near-silent autofocus performance. This focusing motor also enables full-time manual focus override at any time just by rotating the focus ring for refined manual control and focusing as close as 10.6″. The lens barrel is constructed using a Thermally Stable Composite material, which supports working in a wide variety of temperatures and conditions, and the lens mount is constructed from brass for long-term durability and mounting accuracy. Additionally, this lens is also compatible with the optional Sigma USB Dock for fine-tuned control over focusing parameters and other lens characteristics.